Survival in signet ring cell carcinoma varies based on primary tumor location: a Surveillance, Epidemiology, and End Results database analysis

The aim of this study was to investigate the survival of patients with signet ring cell carcinoma (SRCC) based on primary tumor location. Patient data were obtained from the Surveillance, Epidemiology, and End Results database (1988-2012) with ≥200 cases per tumor location. Cox regression analysis was used to investigate prognostic factors of cause-specific survival (CSS). We identified 24,171 patients. Of the patients, 63.4% had gastric SRCC, followed by colon (18.2%), esophageal (5.0%), rectal (3.5%), lung (3.1%), pancreatic (1.8%), breast (1.5%), bladder (1.3%), small intestine (1.1%), and gallbladder SRCC (1.0%). The 5-year CSS was 22.1%, 69.0%, 33.2%, 28.1%, 24.8%, 16.1%, 13.6%, 12.6%, 11.0%, 6.4% in patients with gastric, breast, colon, rectum, bladder, small intestine, esophageal, gallbladder, lung, and pancreatic SRCC, respectively (P < 0.001). Multivariate analyses showed that the primary tumor location was an independent prognostic factor of survival. Patients with lung, small intestine, and bladder SRCC had a comparable CSS to gastric SRCC, while breast and colorectal SRCC had better survival than gastric SRCC. Esophageal, gallbladder, and pancreatic SRCC were significantly associated with poor CSS compared with gastric SRCC. Our study suggests a major difference in survival of SRCC based on the primary tumor locations.